which gives an excess of 10.54554 in the result of the experiment above
the calculated result, from data furnished by former experiments.
This difference, which is by no means very considerable, may arise from
errors which are unavoidable in experiments of this nature, or it may be
owing to the composition of oil not being as yet exactly ascertained. It
proves, however, that there is a great agreement between the results of
our experiments, respecting the combination of caloric, and those which
regard its disengagement.
The following desiderata still remain to be determined, viz. What
quantity of caloric is retained by oxygen, after combining with metals,
so as to convert them into oxyds; What quantity is contained by
hydrogen, in its different states of existence; and to ascertain, with
more precision than is hitherto attained, how much caloric is disengaged
during the formation of water, as there still remain considerable doubts
with respect to our present determination of this point, which can only
be removed by farther experiments. We are at present occupied with this
inquiry; and, when once these several points are well ascertained, which
we hope they will soon be, we shall probably be under the necessity of
making considerable corrections upon most of the results of the
experiments and calculations in this Chapter. I did not, however,
consider this as a sufficient reason for withholding so much as is
already known from such as may be inclined to labour upon the same
subject. It is difficult, in our endeavours to discover the principles
of a new science, to avoid beginning by guess-work; and it is rarely
possible to arrive at perfection from the first setting out.
CHAP. X.
_Of the Combination of Combustible Substances with each other._
As combustible substances in general have a great affinity for oxygen,
they ought likewise to attract, or tend to combine with each other;
_quae sunt eadem uni tertio, sunt eadem inter se_; and the axiom is
found to be true. Almost all the metals, for instance, are capable of
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